1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.server.hdmi;
18
19import android.hardware.hdmi.HdmiDeviceInfo;
20import java.util.ArrayList;
21import java.util.Iterator;
22
23/**
24 * Buffer storage to keep incoming messages for later processing. Used to
25 * handle messages that arrive when the device is not ready. Useful when
26 * keeping the messages from a connected device which are not discovered yet.
27 */
28final class DelayedMessageBuffer {
29    private final ArrayList<HdmiCecMessage> mBuffer = new ArrayList<>();
30    private final HdmiCecLocalDevice mDevice;
31
32    DelayedMessageBuffer(HdmiCecLocalDevice device) {
33        mDevice = device;
34    }
35
36    /**
37     * Add a new message to the buffer. The buffer keeps selected messages in
38     * the order they are received.
39     *
40     * @param message {@link HdmiCecMessage} to add
41     */
42    void add(HdmiCecMessage message) {
43        boolean buffered = true;
44
45        // Note that all the messages are not handled in the same manner.
46        // For &lt;Active Source&gt; we keep the latest one only.
47        // TODO: This might not be the best way to choose the active source.
48        //       Devise a better way to pick up the best one.
49        switch (message.getOpcode()) {
50            case Constants.MESSAGE_ACTIVE_SOURCE:
51                removeActiveSource();
52                mBuffer.add(message);
53                break;
54            case Constants.MESSAGE_INITIATE_ARC:
55            case Constants.MESSAGE_SET_SYSTEM_AUDIO_MODE:
56                mBuffer.add(message);
57                break;
58            default:
59                buffered = false;
60                break;
61        }
62        if (buffered) {
63            HdmiLogger.debug("Buffering message:" + message);
64        }
65    }
66
67    private void removeActiveSource() {
68        // Uses iterator to remove elements while looping through the list.
69        for (Iterator<HdmiCecMessage> iter = mBuffer.iterator(); iter.hasNext(); ) {
70            HdmiCecMessage message = iter.next();
71            if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE) {
72                iter.remove();
73            }
74        }
75    }
76
77    boolean isBuffered(int opcode) {
78        for (HdmiCecMessage message : mBuffer) {
79            if (message.getOpcode() == opcode) {
80                return true;
81            }
82        }
83        return false;
84    }
85
86    void processAllMessages() {
87        // Use the copied buffer.
88        ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<HdmiCecMessage>(mBuffer);
89        mBuffer.clear();
90        for (HdmiCecMessage message : copiedBuffer) {
91            mDevice.onMessage(message);
92            HdmiLogger.debug("Processing message:" + message);
93        }
94    }
95
96    /**
97     * Process messages from a given logical device. Called by
98     * {@link NewDeviceAction} actions when they finish adding the device
99     * information.
100     * <p>&lt;Active Source&gt; is processed only when the TV input is ready.
101     * If not, {@link #processActiveSource()} will be invoked later to handle it.
102     *
103     * @param address logical address of CEC device which the messages to process
104     *        are associated with
105     */
106    void processMessagesForDevice(int address) {
107        ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<HdmiCecMessage>(mBuffer);
108        mBuffer.clear();
109        HdmiLogger.debug("Checking message for address:" + address);
110        for (HdmiCecMessage message : copiedBuffer) {
111            if (message.getSource() != address) {
112                mBuffer.add(message);
113                continue;
114            }
115            if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE
116                    && !mDevice.isInputReady(HdmiDeviceInfo.idForCecDevice(address))) {
117                mBuffer.add(message);
118                continue;
119            }
120            mDevice.onMessage(message);
121            HdmiLogger.debug("Processing message:" + message);
122        }
123    }
124
125    /**
126     * Process &lt;Active Source&gt;.
127     *
128     * <p>The message has a dependency on TV input framework. Should be invoked
129     * after we get the callback
130     * {@link android.media.tv.TvInputManager.TvInputCallback#onInputAdded(String)}
131     * to ensure the processing of the message takes effect when transformed
132     * to input change callback.
133     *
134     * @param address logical address of the device to be the active source
135     */
136    void processActiveSource(int address) {
137        ArrayList<HdmiCecMessage> copiedBuffer = new ArrayList<HdmiCecMessage>(mBuffer);
138        mBuffer.clear();
139        for (HdmiCecMessage message : copiedBuffer) {
140            if (message.getOpcode() == Constants.MESSAGE_ACTIVE_SOURCE
141                    && message.getSource() == address) {
142                mDevice.onMessage(message);
143                HdmiLogger.debug("Processing message:" + message);
144            } else {
145                mBuffer.add(message);
146            }
147        }
148    }
149}
150